I need to create a LINQ sentence that does the same as this SQL sentence but I can't solve it...
SELECT l.Id, l.Url, t.Name, t.LanguageCode
FROM link l
LEFT OUTER JOIN linktr t ON t.Id = (SELECT tt.Id FROM linktr tt WHERE tt.LinkId = l.Id AND (tt.LanguageCode = 'en-EN' OR tt.LanguageCode = 'es-ES') ORDER BY (tt.LanguageCode = 'en-EN') DESC, tt.LanguageCode LIMIT 1)
ORDER BY l.OrderPos
Table Link
Id, Url
Table LinkTr
Id, LinkId, Name, LanguageCode
The table link contains the Url of the link while the LinkTr contains the name and it can cointain multiple languages
I want to select all the links we have in the links database and for each link I want to show JUST ONE language, the one that corresponds to the current language if exists, but if it doesn't exist I have to show the one that corresponds to the default language. If no one of them exist it wouldn't show that record.
For this example the default language is es-ES and the current one is en-EN.
How can I do this using LINQ?
Thanks in advance
EDIT
If I use this LINQ expression it works only if I comment the ORDER line, but without the ORDER line (.OrderBy(p3 => p3.LanguageCode == currentLanguage)) it takes the first record in the db by Id, but not the current language first.
var queryString = from i in _dbContext.Links
let p = _dbContext.LinksTrs.Where(p2 => i.Id == p2.LinkId && (p2.LanguageCode == currentLanguage || p2.LanguageCode == defaultLanguage))
.OrderBy(p3 => p3.LanguageCode == currentLanguage)
.FirstOrDefault()
orderby i.OrderPos
select new LinksWebListModel
{
Id = i.Id,
Name = (p == null) ? "" : p.Name,
Url = i.Url,
Summary = (p == null) ? "" : p.Summary,
};
EDIT 2
I'm suing EF6 and my entities, which I can't change, are these:
public class Link : EntityBase
{
public int Id { get; set; }
public int OrderPos { get; set; }
public string Url { get; set; }
public virtual IEnumerable<LinkTr> Translations { get; set; }
}
public class LinkTr
{
public int Id { get; set; }
public string Name { get; set; }
public string LanguageCode { get; set; }
public int LinkId { get; set; }
public virtual Link Link { get; set; }
}
EDIT 3
it would be something like this...
var queryString = (from entity in _dbContext.Links
let translation = _dbContext.LinksTrs
.Where(p2 => p2.LinkId == entity.Id)
.Where(p3 => p3.LanguageCode == currentLanguage || p3.LanguageCode == defaultLanguage)
.OrderBy(p4 => p4.LanguageCode)
.FirstOrDefault()
orderby entity.OrderPos descending
select new LinksWebListModel()
{
Id = entity.Id,
Name = translation.Name,
Url = entity.Url,
Summary = translation.Summary,
});
buit the problems here are 2:
- I need to return the record (Links) only if there is a row in the sub query (LinksTrs)
- Also I'd need to order the subquery by "currentLanguage" first and then "defaultLanguage" and then the rest. If I add this to the sub query I get an error:
.OrderBy(p4 => p4.LanguageCode == currentLanguage)
.ThenBy(p5 => p5.LanguageCode == defaultLanguage)
.ThenBy(p6 => p6.LanguageCode)
Do you have an idea on how to order by certain values, for example if I have these languages "es-ES", "en-EN", "it-IT", "fr-FR" for example to get first "it-IT", then "es-ES" and then order by name...
Related
I inherited the code below and was hoping someone could explain it to me. The model definition is fine, but I am not understanding the string Minor1 setup. The SQL query looks backwards. Is this a normal practice? I tried putting the query in the normal order (select, from, where) and it did not work.
Example for model:
[Table("MINORS")]
public class VerifyDataModel_MINORS
{
[Key]
public string MINORS_ID { get; set; }
public string MINORS_DESC { get; set; }
}
string Minor1 = (from A in db.VerifyDataModel_STUDENT_PROGRAM
join B in db.VerifyDataModel_STPR_STATUS on A.STUDENT_PROGRAMS_ID equals B.STUDENT_PROGRAMS_ID into AB
from AB1 in AB.Where(B => B.POS == 1).DefaultIfEmpty()
join C in db.VerifyDataModel_STPR_MINOR_LISTS on A.STUDENT_PROGRAMS_ID equals C.STUDENT_PROGRAMS_ID into ABC
from ABC1 in ABC.Where(C => C.STPR_MINORS.Substring(0, 2) != "XX").DefaultIfEmpty()
join D in db.VerifyDataModel_MINOR on ABC1.STPR_MINORS equals D.MINORS_ID into ABCD
from ABCD1 in ABCD.DefaultIfEmpty()
where AB1.STPR_STATUS == "A"
where ABC1.STUDENT_PROGRAMS_ID.Substring(8, 5) != "GENED"
where A.STUDENT_PROGRAMS_ID.Substring(0, 7) == personId
where ABC1.STPR_MINOR_END_DATE == null
select ABCD1.MINORS_DESC).Min();
I have two tables DefaultAttributes and CustomAttributes.
DefaultAttributeTable:
1. Id
2. Product
4. Description
CustomAtrributeTable:
1. Id
2. DefaultAttributeMappingId(FK from DefaultAttributeTable)
3. CustomAtrributeName
4. CustomeAttributeValue
Entries made by user:
user update the values Product -> Vegetables, Description -> House Hold Item, IsOrganic(Custom Attribute created) -> True and IsDisposable(Custom Attribute created) -> True
user update the values Product -> Fruits, Description -> House Hold Item, IsOrganic(Custom Attribute created) -> True and IsDisposable(Custom Attribute created) -> True
user update the values Product -> Plastic, Description -> House Hold Item, IsOrganic(Custom Attribute created) -> False and and IsDisposable(Custom Attribute created) -> False
Then the values will be updated in the table will
DeafaultAtrributeTable:
CustomAttributeTable:
I want to combine the two tables and select the Id, product, IsOrganic, IsDisposable and filter the values based on the isorganic column. Also the custom attribute column name should be taken form the CustomAtrributeTable. Please suggest to me how to achieve it in SQL and Linq Query. The filtered value should be
You may try this in SQL
select DA.Id, DA.Product, CA.CustomeAttributeValue as IsOrganic
from DeafaultAtrributeTable as DA inner join CustomAttributeTable as CA
on DA.Id = CA.DefaultAttributeMappingId
In LINQ
var query =
from DA in DeafaultAtrributeTable
join CA in CustomAttributeTable on DA.ID equals CA.DefaultAttributeMappingId
where CA.CustomeAttributeValue == true
select new { Id = DA.Id, Product = DA.Product, IsOrganic = CA.CustomeAttributeValue };
or LINQ extension method is
var query = DeafaultAtrributeTable // your starting point - table in the "from" statement
.Join(CustomAttributeTable , // the source table of the inner join
DA => DA.ID, // Select the primary key (the first part of the "on" clause in an sql "join" statement)
CA => CA.DefaultAttributeMappingId, // Select the foreign key (the second part of the "on" clause)
(DA, CA) => new { Id = DA.Id, Product = DA.Product, IsOrganic =
CA.CustomeAttributeValue }) // selection
.Where(RES => RES.CA.CustomeAttributeValue == true); // where statement
try this
public class Filtered
{
public int ProductId { get; set; }
public string ProductName { get; set; }
public bool? IsOrganic { get; set; }
public bool? IsDisposable { get; set; }
}
var result = defaultAttributeTable.Join(customAtrributeTable, DAT => DAT.Id, CAT => CAT.DefaultAttributeTableId, (DAT, CAT) =>
new Filtered
{
//your join with null values for opposing isdisposable and isorganic
ProductId = DAT.Id,
IsDisposable = CAT.CustomAtrributeName == "IsDisposable" ? (bool?)CAT.CustomeAttributeValue : null,
IsOrganic = CAT.CustomAtrributeName == "IsOrganic" ? (bool?)CAT.CustomeAttributeValue : null,
ProductName = DAT.Product
}).GroupBy(q => q.ProductId) //group it by productid
.Select(q =>
new Filtered
{
//this will flatten opposing isorganic and isdisposable
ProductId = q.Key,
IsDisposable = q.First(e => e.IsDisposable.HasValue).IsDisposable.Value,
IsOrganic = q.First(e => e.IsOrganic.HasValue).IsOrganic.Value,
ProductName = q.First(e => e.ProductId == q.Key).ProductName
}).ToList();
I have the following code:
public class WorkOrderByUserId : AbstractMultiMapIndexCreationTask<WorkOrderByUserId.Result>
{
public WorkOrderByUserId()
{
this.AddMap<WorkOrder>(items
=> from item in items
select new Result
{
OwnerId = item.OwnerId,
WorkOrder = new WorkOrderLookupDto
{
Id = item.Id,
Name = item.EventName
},
WorkOrders = null
});
this.AddMap<Invoice>(items
=> from item in items
select new Result
{
OwnerId = item.WorkOrder.OwnerId,
WorkOrder = new WorkOrderLookupDto
{
Id = item.WorkOrder.Id,
Name = item.WorkOrder.EventName
},
WorkOrders = null
});
this.Reduce = results => from result in results
group result by result.OwnerId
into g
select new Result
{
OwnerId = g.Key,
WorkOrders = g.Select(x => x.WorkOrder),
WorkOrder = null
};
this.Indexes.Add(x => x.OwnerId, FieldIndexing.Default);
}
public class Result
{
public string OwnerId { get; set; }
public IEnumerable<WorkOrderLookupDto> WorkOrders { get; set; }
public WorkOrderLookupDto WorkOrder { get; set; }
}
}
It gets me very close to where I want to be, however I seem to be missing something and I'm losing information and I'm not sure why.
Using the Map/Reduce Visualizer I notice the MAP is displaying the Results (i.e. WorkOrders is populated, and WorkOrder is null)
As this point I was expecting to have a bunch of items with NULL WorkOrders and a valid WorkOrder, which I expected to reduce down into the WorkOrders collection.
When I look at the final reduce in the visualizer, I notice my WorkOrder is NULL and my WorkOrders are missing entirely.
And when I look at the FINAL result of the Index I see what I'm looking for, just without the actual data I'm looking for.
What do I need to change to get my final WorkOrders to NOT be NULL?
I was able to get my desired result using the following code:
public class WorkOrderByUserId : AbstractMultiMapIndexCreationTask<WorkOrderByUserId.Result>
{
public WorkOrderByUserId()
{
this.AddMap<WorkOrder>(items
=> from item in items
select new Result
{
OwnerId = item.OwnerId,
WorkOrders = new[]
{
new WorkOrderLookupDto
{
Id = item.Id,
Name = item.EventName
}
}
});
this.AddMap<Invoice>(items
=> from item in items
select new Result
{
OwnerId = item.WorkOrder.OwnerId,
WorkOrders = new[]
{
new WorkOrderLookupDto
{
Id = item.WorkOrder.Id,
Name = item.WorkOrder.EventName
}
}
});
this.Reduce = results => from result in results
group result by result.OwnerId
into g
select new Result
{
OwnerId = g.Key,
WorkOrders = g.SelectMany(x => x.WorkOrders)
};
this.Indexes.Add(x => x.OwnerId, FieldIndexing.Default);
}
public class Result
{
public string OwnerId { get; set; }
public IEnumerable<WorkOrderLookupDto> WorkOrders { get; set; }
}
}
I Have 4 tables:
Position Table:
| Position | PositionId |
| driver | 1 |
| clerk | 2 |
position Skill table:
| SkillId | skill | PositionId |
| 1 | driving | 1 |
| 2 | drifting | 1 |
Worker table:
| Name | WorkerId |
| John | 1 |
| alex | 2 |
Worker skill table:
| skillId | skill | WorkerId |
| 1 | driving | 1 |
| 2 | drifting | 1 |
I join the position table with position Skill table
and worker table with worker skill
What I'm having trouble with is how can I compare the two joined tables to have a result of
for example:
I need to know who's worker have all the specific skills that the position have
Like:
I Select position with positionId of 1 and have the skillname of driving and drifting
I need to get the Worker with the same skills with driving and drifting also
so far i got this:
var PositionsWithSkills = (from a in db.Client_Customer_Position
where a.ID == position
select new
{
PositionID = a.ID,
RequiredSkills = (from b in db.Client_Customer_Position_Skills
where b.ClientCusPosId == a.ID
select b.SkillName)
}).ToList();
var WorkersWithSkills = (from x in db.Workers
select new
{
workerId = x.ID,
Skills = (from y in db.Worker_Skills
where y.Worker_ID == x.ID
select y.SkillName)
}).ToList();
var PositionWithSkilledWorkers = (from pos in PositionsWithSkills
select new
{
PositionId = pos.PositionID,
Workers = (from worker in WorkersWithSkills
where pos.RequiredSkills.All(skill => worker.Skills.Any(workerSkill => workerSkill == skill))
select worker.workerId)
}).ToList();
the two query works well.. but the last query where i must compare the two query =.. i cant get the worker id
and can i turn this to a stored proc?
Sorry if am wrong. What I got to know from your question is you want the workers list satisfying all the skills of the position you pass. If this is what you want you may try this:
var workerWithallSkill = (from u in db.workerList join x in db.workerSkillList on u.WorkerId equals x.WorkerId
where ((from y in db.workerSkillList where y.WorkerId == u.WorkerId select y).Count() == (from p in db.positionSkillList where p.PositionId == 1("pass your positionId here") select p).Count())
select u).ToList().Distinct();
or if you want to use lambda expression you can use this
var workerWithallSkill = (from u in workerList join x in workerSkillList on u.WorkerId equals x.WorkerId where (workerSkillList.Where(y=> y.WorkerId == u.WorkerId).Count() == positionSkillList.Where(p=>p.PositionId == 1).Count()) select u).ToList().Distinct();
For more understanding you can try the below code:
using System;
using System.Collections.Generic;
using System.Linq;
using System.Text;
namespace ConsoleApplication8
{
class Program
{
static void Main(string[] args)
{
IList<Position> positionList = new List<Position>() {
new Position(){ position="Driver", PositionId=1}
,new Position(){ position="clerk", PositionId=2}
};
IList<PositionSkill> positionSkillList = new List<PositionSkill>() {
new PositionSkill(){ Skill = "driving",skillid = 1,PositionId = 1}
,new PositionSkill(){ Skill = "drifting",skillid = 2,PositionId = 1}
};
IList<Worker> workerList = new List<Worker>() {
new Worker(){ name = "John",WorkerId = 1}
,new Worker(){ name = "alex",WorkerId = 2}
};
IList<WorkerSkill> workerSkillList = new List<WorkerSkill>(){
new WorkerSkill(){Skill = "driving",skillid = 1,WorkerId = 2}
, new WorkerSkill(){Skill = "drifting",skillid = 2,WorkerId = 2}
};
var workerWithallSkill = (from u in workerList join x in workerSkillList on u.WorkerId equals x.WorkerId where (workerSkillList.Where(y => y.WorkerId == u.WorkerId).Count() == positionSkillList.Where(p => p.PositionId == 1).Count()) select u).ToList().Distinct();
foreach (var worker in workerWithallSkill)
{
Console.WriteLine(worker.name);
}
Console.ReadLine();
}
}
public class Position
{
public string position { get; set; }
public int PositionId { get; set; }
}
public class PositionSkill
{
public int skillid { get; set; }
public string Skill { get; set; }
public int PositionId { get; set; }
}
public class Worker
{
public string name { get; set; }
public int WorkerId { get; set; }
}
public class WorkerSkill
{
public int skillid { get; set; }
public string Skill { get; set; }
public int WorkerId { get; set; }
}
}
if a worker has skills from different positions the above code will not work, if this is the scenario try the below code:
var WorkerPositionSkill = from p in db.positionSkillList join q in db.workerSkillList on p.skillid equals q.skillid select new { posSkill = p, workerSkill = q };
var workerWithallSkill = (from u in db.workerList join x in db.workerSkillList on u.WorkerId equals x.WorkerId where (WorkerPositionSkill.Where(y => y.workerSkill.WorkerId == u.WorkerId && y.posSkill.PositionId == 1).Count() == db.positionSkillList.Where(p => p.PositionId == 1).Count()) select u).ToList().Distinct();
This is highly unlikely to work with Linq To SQL because...its a huge steaming pile of #$%&. But this Linq query should given a sufficiently magical IQueryProvider give the right SQL. I've seen some very magical things come from Entity Framework.
var PositionsWithSkills = from a in db.Client_Customer_Position
where a.ID == position
select new
{
PositionID = a.ID,
RequiredSkills = (from b in db.Client_Customer_Position_Skills
where b.ClientCusPosId == a.ID
select b.SkillName)
};
var WorkersWithSkills = from x in db.Workers
select new
{
workerId = x.ID,
Skills = (from y in db.Worker_Skills
where y.Worker_ID == x.ID
select y.SkillName)
};
var PositionWithSkilledWorkers = from pos in PositionsWithSkills
from worker in WorkersWithSkills
where pos.RequiredSkill.All(worker.Skills.Contains)
group worker.Name by pos.PositionID;
PS please learn to use associations as opposed to join/where. If you are going to use join/where, you might as well just use SQL.
var PositionsWithSkills = (from a in Positions select new {
PositionID = a.PositionId,
RequiredSkills = (from b in PositionSkills where b.PositionId == a.PositionId select b.skillId).ToList()
}).ToList();
var WorkersWithSkills = (from x in Workers select new {
Name = x.Name,
Skills = (from y in WorkerSkills where y.WorkerId == x.WorkerID select y.skillId).ToList()
}).ToList();
var PositionWithSkilledWorkers = (from pos in PositionsWithSkills select new {
PositionId = pos.PositionID,
Workers = (from worker in WorkersWithSkills where pos.RequiredSkills.All(skill => worker.Skills.Any(workerSkill => workerSkill == skill)) select worker.Name).ToList()
}).ToList();
i think, your database's tables have not been designed correctly...
you need a relation between worker skill and position skill, i think your tables must be desinged like this:
Skill table: SkillID, Skill
Position table: PositionID, Position
PositionSkill table: ID, SkillID, PositionID
Worker table: WorkerID, Name
WorkerSkill table: ID, SkillID, WorkerID
but by this way you designed your tables, if assume skill field (description of skills) are the same in worker skill and position skill, we can use this as a relation, and your query can be like this:
// skills of specific position
var PositionSkills = Context.PositionSkill.Where(u => u.PositionId == 1);
var WorkersWithSkills = Context.Worker
.Join(Context.WorkerSkill,
worker => worker.WorkerId,
workerSkill => workerSkill.WorkerId,
(worker, workerSkill) => new { worker, workerSkill })
.GroupBy(u => u.worker)
.Select(u => new
{
u.Key.WorkerId,
u.Key.Name,
Skills = u.Select(t => t.workerSkill.skill)
});
var SkilledWorkers = WorkersWithSkills
.Where(u => PositionSkills.All(t => u.Skills.Contains(t.skill)))
.ToList();
if you wont change your database's tables, you can add a join table between position skill and worker skill like:
WorkerPositionSkill: PositionSkillID, WorkerSkillID
Here is a LinqPad program that returns the result, { Worker = John, Position = Driver}. If I understand your requirements you want to find a worker who satisfies the conditions where the worker has all the skills required for Position = 1, which is driving and drifting skills. The query returns two rows the following [{worker = John, Position = Driver}, {worker = John, Position = Driver}]. I had to use distinct to display it once. The reason for two rows is he satisfies both driving and drifting job skills. If the position required 4 skills in which the worker met, there would be 4 duplicate rows. The unique fixes that problem. Hope this helps you along.
I created this solution in LinqPad, which is great tool with hundred's of very well documented linq query examples.
void Main()
{
// Table Setup
// ************
var position = new List<Position>();
position.Add(new Position { Id = 1, Name = "driver" });
position.Add(new Position { Id = 2, Name = "clerk" });
var positionSkill = new List<PositionSkill>();
positionSkill.Add(new PositionSkill { Id = 1, Skill = "driving", PositionId = 1 });
positionSkill.Add(new PositionSkill { Id = 2, Skill = "drifting", PositionId = 1 });
var worker = new List<Worker>();
worker.Add(new Worker { Id = 1, Name = "John" });
worker.Add(new Worker { Id = 2, Name = "alex" });
var workerSkill = new List<WorkerSkill>();
workerSkill.Add(new WorkerSkill { Id = 1, Skill = "driving", WorkerId = 1 });
workerSkill.Add(new WorkerSkill { Id = 2, Skill = "drifting", WorkerId = 1 });
// The Query
// *********
var positionValue = 1;
var r = from p in position
join ps in positionSkill on p.Id equals ps.PositionId
join ws in workerSkill on ps.Skill equals ws.Skill
join w in worker on ws.WorkerId equals w.Id
where p.Id == positionValue
select new {
PositionName = p.Name,
WorkerName = w.Name
};
// Get Distinct Names
r.Distinct().Dump();
}
// Define other methods and classes here
public class Position
{
public int Id { get; set; }
public string Name { get; set; }
}
public class PositionSkill
{
public int Id { get; set; }
public string Skill { get; set; }
public int PositionId { get; set; }
}
public class Worker
{
public int Id { get; set; }
public string Name { get; set; }
}
public class WorkerSkill
{
public int Id { get; set; }
public string Skill { get; set; }
public int WorkerId { get; set; }
}
I'm trying to work with grouped data coming back from SQL.
The method I'm writing is to provide the data for a "Case Status Overview" screen.
It must produce a nested XML document.
Now, I could do it the easy way, but I'm trying to learn whether it's possible to use the linq "group by" statement and then to project the data already nested. (the easy way would be just to pull back the data in a tabular fashion from the database and then for-loop through it forming the Xml document for output)
Here is the data hierarchy:
Every Case has a DebtType and every DebtType has a Client.
Here is the SQL that retrieves the data:
SELECT ClientNames.ClientID ,
ClientNames.ClientCode ,
ClientNames.ClientName ,
DebtTypes.DebtTypeID ,
DebtTypes.DebtTypeShortDesc ,
DebtTypes.DebtTypeLongDesc ,
Cases.CurrentStateCode ,
SUM(1 - CAST(Cases.CaseClosed AS INT)) AS OpenCaseCount ,
SUM(CAST(Cases.CaseClosed AS INT)) AS ClosedCaseCount ,
SUM(CAST(Cases.CaseOnHold AS INT)) AS OnHoldCaseCount ,
SUM(CAST(Cases.CaseReferred AS INT)) AS ReferredCaseCount ,
COUNT(Cases.CaseID) AS TotalCaseCount ,
SUM(Cases.CaseTotalPaid) AS TotalAmountPaid ,
SUM(Cases.CaseCurrentOutstandingAmount) AS TotalAmountOutstanding,
SUM(Cases.CaseTotalDebtWrittenOff) AS TotalAmountWrittenOff ,
SUM(Cases.CaseTotalDebtCancelled) AS TotalAmountCancelled
FROM ClientNames
INNER JOIN ClientDebtTypes
ON ClientNames.ClientID = ClientDebtTypes.ClientID
INNER JOIN DebtTypes
ON ClientDebtTypes.DebtTypeID = DebtTypes.DebtTypeID
INNER JOIN Cases
ON ClientDebtTypes.ClientDebtTypeID = Cases.CaseClientDebtTypeID
GROUP BY ClientNames.ClientID ,
ClientNames.ClientCode ,
ClientNames.ClientName ,
DebtTypes.DebtTypeID ,
DebtTypes.DebtTypeShortDesc,
DebtTypes.DebtTypeLongDesc ,
Cases.CurrentStateCode
ORDER BY ClientNames.ClientID,
DebtTypes.DebtTypeID,
CurrentStateCode
Using Linqer it converts it to:
from clientnames in db.ClientNames
join clientdebttypes in db.ClientDebtTypes on clientnames.ClientID equals clientdebttypes.ClientID
join debttypes in db.DebtTypes on clientdebttypes.DebtTypeID equals debttypes.DebtTypeID
join cases in db.Cases on new { ClientDebtTypeID = clientdebttypes.ClientDebtTypeID } equals new { ClientDebtTypeID = cases.CaseClientDebtTypeID }
group new {clientnames, debttypes, cases} by new {
clientnames.ClientID,
clientnames.ClientCode,
clientnames.ClientName1,
debttypes.DebtTypeID,
debttypes.DebtTypeShortDesc,
debttypes.DebtTypeLongDesc,
cases.CurrentStateCode
} into g
orderby
g.Key.ClientID,
g.Key.DebtTypeID,
g.Key.CurrentStateCode
select new {
ClientID = (System.Int32?)g.Key.ClientID,
g.Key.ClientCode,
g.Key.ClientName1,
DebtTypeID = (System.Int32?)g.Key.DebtTypeID,
g.Key.DebtTypeShortDesc,
g.Key.DebtTypeLongDesc,
g.Key.CurrentStateCode,
OpenCaseCount = (System.Int64?)g.Sum(p => 1 - Convert.ToInt32(p.cases.CaseClosed)),
ClosedCaseCount = (Int32?)g.Sum(p => Convert.ToInt32(p.cases.CaseClosed)),
OnHoldCaseCount = (Int32?)g.Sum(p => Convert.ToInt32(p.cases.CaseOnHold)),
ReferredCaseCount = (Int32?)g.Sum(p => Convert.ToInt32(p.cases.CaseReferred)),
TotalCaseCount = (Int64?)g.Count(p => p.cases.CaseID != null),
TotalAmountPaid = (System.Decimal?)g.Sum(p => p.cases.CaseTotalPaid),
TotalAmountOutstanding = (System.Decimal?)g.Sum(p => p.cases.CaseCurrentOutstandingAmount),
TotalAmountWrittenOff = (System.Decimal?)g.Sum(p => p.cases.CaseTotalDebtWrittenOff),
TotalAmountCancelled = (System.Decimal?)g.Sum(p => p.cases.CaseTotalDebtCancelled)
}
Now as I mentioned, I could stop there and right a for loop to create the Xml data.
But I'm trying to create a nested group (IGrouping<ClientName,IGrouping<DebtType,SummaryClass>>)
and then project the data in a nested format.
Now we're using LinqToXsd to create strong type wrappers for out Xml documents, but essentially all this means is that out output type is:
private class ClientSummary
{
public string ClientName { get; set; }
public IList<DebtTypeSummary> DebtTypes { get; set; }
}
private class DebtTypeSummary
{
public string DebtType { get; set; }
public IList<StateCodeSummary> StateCodes { get; set; }
}
private class StateCodeSummary
{
public string StateCode { get; set; }
public int TotalCount { get; set; }
public decimal TotalAmountPaid { get; set; }
//etc
//etc
//etc
}
Now I got as far as writing the following Linq:
var grouping = from cases in db.Cases
join clientdebttypes in db.ClientDebtTypes on cases.CaseClientDebtTypeID equals clientdebttypes.ClientID
join debttypes in db.DebtTypes on clientdebttypes.DebtTypeID equals debttypes.DebtTypeID
group cases by new ClientDebtTypePair() { ClientDebtType = clientdebttypes, DebtType = debttypes } into casesByClientDebtTypes
join clientnames in db.ClientNames on casesByClientDebtTypes.Key.ClientDebtType.ClientName equals clientnames
group casesByClientDebtTypes by clientnames;
var projected = from casesByClientDebtTypes in grouping
let client = casesByClientDebtTypes.Key
select new LoadCaseStatusOverviewScreenOutput.ClientsLocalType()
{
Client = new Client()
{
ClientID = client.ClientID,
DisplayName = client.ClientName1,
},
DebtTypes = from cases in casesByClientDebtTypes
let debttype = cases.Key.DebtType
select new LoadCaseStatusOverviewScreenOutput.ClientsLocalType.DebtTypesLocalType()
{
DebtType = new DebtType()
{
DebtTypeID = debttype.DebtTypeID,
Description = debttype.DebtTypeLongDesc,
DisplayName = debttype.DebtTypeShortDesc,
},
StatesCodes = from cases2 in cases
select new LoadCaseStatusOverviewScreenOutput.ClientsLocalType.DebtTypesLocalType.StatesCodesLocalType()
{
ClosedCasesCount = cases2.Sum(p => Convert.ToInt32(p.cases.CaseClosed))
which joins and groups the database tables and then tries to project the result a ClientSummary (the class names are different but that's because the above is a simplified view of the output classes). I fail completely when I've drilled all the way down to the Cases table and I find that I don't really understand how to do agregate functions. They appear to only be available on IGrouping<K, T>s and it seems I've just got confused.
I need to also ensure that the summaries are calculated server side, pulling back millions of cases would be bad.
Can anybody help me with this one? Is this even possible?
Regards,
James.
-------### UPDATE 1 ###-------
OK, been working on this again today.
I decided to use Linq2SQL to pull pack 2D data and then reformat it using Linq2Objects.
Here is what I started with:
var sql = from clientnames in db.ClientNames
join clientdebttypes in db.ClientDebtTypes on clientnames.ClientID equals clientdebttypes.ClientID
join debttypes in db.DebtTypes on clientdebttypes.DebtTypeID equals debttypes.DebtTypeID
join cases in db.Cases on new { ClientDebtTypeID = clientdebttypes.ClientDebtTypeID } equals new { ClientDebtTypeID = cases.CaseClientDebtTypeID }
group new { clientnames, debttypes, cases } by new
{
clientnames.ClientID,
clientnames.ClientCode,
clientnames.ClientName1,
debttypes.DebtTypeID,
debttypes.DebtTypeShortDesc,
debttypes.DebtTypeLongDesc,
cases.CurrentStateCode
} into g
orderby
g.Key.ClientID,
g.Key.DebtTypeID,
g.Key.CurrentStateCode
select new
{
Client = new Client{ ClientID = g.Key.ClientID, DisplayName = g.Key.ClientName1 },
DebtType = new DebtType{ DebtTypeID = g.Key.DebtTypeID, DisplayName = g.Key.DebtTypeShortDesc, Description = g.Key.DebtTypeLongDesc },
StateSummary = new LoadCaseStatusOverviewScreenOutput.ClientsLocalType.DebtTypesLocalType.StatesCodesLocalType()
{
StateCode = g.Key.CurrentStateCode,
OpenCasesCount = g.Sum(p => 1 - Convert.ToInt32(p.cases.CaseClosed)),
ClosedCasesCount = g.Sum(p => Convert.ToInt32(p.cases.CaseClosed)),
OnHoldCasesCount = g.Sum(p => Convert.ToInt32(p.cases.CaseOnHold)),
ReferredCasesCount = g.Sum(p => Convert.ToInt32(p.cases.CaseReferred)),
TotalCasesCount = g.Count(p => p.cases.CaseID != null),
TotalAmountPaid = g.Sum(p => p.cases.CaseTotalPaid),
TotalAmountOutstanding = g.Sum(p => p.cases.CaseCurrentOutstandingAmount),
TotalAmountWrittenOff = g.Sum(p => p.cases.CaseTotalDebtWrittenOff),
TotalAmountCancelled = g.Sum(p => p.cases.CaseTotalDebtCancelled),
}
};
var res = sql.ToList();
output.Clients = (from results in res
group results by results.Client into resultsByClient
from resultsByDebtType in
(from results in resultsByClient
group results by results.DebtType)
group resultsByDebtType by resultsByClient.Key into resultsByDebtTypeByClient
select new LoadCaseStatusOverviewScreenOutput.ClientsLocalType()
{
Client = resultsByDebtTypeByClient.Key,
DebtTypes = (from resultsByDebtType in resultsByDebtTypeByClient
select new LoadCaseStatusOverviewScreenOutput.ClientsLocalType.DebtTypesLocalType()
{
DebtType = resultsByDebtType.Key,
StatesCodes = (from results in resultsByDebtType
let summary = results.StateSummary
select results.StateSummary).ToList()
}).ToList()
}).ToList();
That runs, but produces one Client/DebtType/Summary set for every result. So even though there is only one client in this case, I end up with 1300 clients, all identical.
I simplified it to the following:
output.Clients = (from results in res
group results by results.Client into resultsByClient
select new LoadCaseStatusOverviewScreenOutput.ClientsLocalType()
{
Client = resultsByClient.Key,
DebtTypes = null,
}).ToList();
That produces 1300 clients. Next I tried this:
output.Clients = (from results in res
group results by results.Client.ClientID into resultsByClient
select new LoadCaseStatusOverviewScreenOutput.ClientsLocalType()
{
Client = new Client { ClientID = resultsByClient.Key },
DebtTypes = null,
}).ToList();
And THAT produces ONE client (hurray!). Except I loose all the client information (boo!)
Guessing that as it's comparing client by refernce instead of by content I wrote the following:
public partial class Client
{
public static bool operator ==(Client left, Client right)
{
return left.ClientID == right.ClientID;
}
public static bool operator !=(Client left, Client right)
{
return left.ClientID != right.ClientID;
}
public override int GetHashCode()
{
return ClientID;
}
}
That did nothing. It repeatedly calls GetHashCode(), which I fudged to force it to return the same hash code for any matching ClientID, but it still created 1300 Client groups.
Regards,
James.
-------### UPDATE 2 ###-------
OK, I thought I would have a go at making the Linq2Sql output only simple values for grouping by:
g.Key.ClientID,
g.Key.ClientName1,
g.Key.DebtTypeID,
g.Key.DebtTypeShortDesc,
g.Key.DebtTypeLongDesc,
And then changed the test Linq2Objects to:
output.Clients = (from results in res
group results by new { ClientID = results.ClientID, DisplayName = results.ClientName1 } into resultsByClient
select new LoadCaseStatusOverviewScreenOutput.ClientsLocalType()
{
Client = new Client { ClientID = resultsByClient.Key.ClientID, DisplayName = resultsByClient.Key.DisplayName },
DebtTypes = null,
}).ToList();
That works. So anonymous types compare in the way I want them to, by content not reference (apparently)
This does not:
output.Clients = (from results in res
group results by new SiDemClient { ClientID = results.ClientID, DisplayName = results.ClientName1 } into resultsByClient
select new LoadCaseStatusOverviewScreenOutput.ClientsLocalType()
{
Client = resultsByClient.Key,//new Client { ClientID = resultsByClient.Key.ClientID, DisplayName = resultsByClient.Key.DisplayName },
DebtTypes = null,
}).ToList();
That still creates 1300 groups.
So, anonymous types compare in a magical way that I don't understand. How can I make my Client class compare like an anonymous type?
Regards,
James.
-------### SOLUTION FOUND ###-------
-------### MANY THANKS TO Enigmativity ###-------
I needed to override the Equals() method instead of implementing the == operator.
Now the grouping works and I have a wonderful Xml document to reutrn!
public partial class SiDemClient
{
public override bool Equals(object obj)
{
if (obj is SiDemClient)
{
return this.ClientID.Equals(((SiDemClient)obj).ClientID);
}
return false;
}
public override int GetHashCode()
{
return ClientID;
}
}
Many Thanks,
James.
When you override GetHashCode you must also override Equals. The == & != operators are irrelevant.
Try with this:
public partial class Client
{
public override bool Equals(object obj)
{
if (obj is Client)
{
return this.ClientID.Equals(((Client)obj).ClientID);
}
return false;
}
public override int GetHashCode()
{
return this.ClientID.GetHashCode();
}
}
See if that helps.